"That which I say necessitates and determinates every action is the sum of all those things which, being now existent, conduce and concur to the production of the action hereafter, whereof if any one thing were wanting, the effect could not be produced. This concourse of causes, whereof every one is determined to be such as it is by a like concourse of former causes, may well be called the decree of God." (Of Liberty and Necessity, 1654, § 11)

For Hobbes, the idea that one could ever do otherwise was a contradiction and nonsense.

"I hold that ordinary definition of a free agent, namely that a free agent is that which, when all things are present which are needful to produce the effect, can nevertheless not produce it, implies a contradiction and is nonsense; being as much as to say the cause may be sufficient, that is necessary, and yet the effect shall not follow." (§ 32)

But Hobbes was also the modern inventor of compatibilism, the idea that necessary causes and voluntary actions are compatible. (In antiquity, compatibilism was first proposed by the Stoic Chrysippus)

"when first a man has an appetite or will to something, to which immediately before he had no appetite nor will, the cause of his will is not the will itself, but something else not in his own disposing. So that whereas it is out of controversy that of voluntary actions the will is the necessary cause, and by this which is said the will is also caused by other things whereof it disposes not, it follows that voluntary actions have all of them necessary causes and therefore are necessitated." (§ 30)

In his 1656 book The Questions concerning Liberty, Necessity, and Chance, Hobbes presents the religious controversy in his day between the Catholic church, which endorsed a "free will" for man, and the various protestant sects, most of which denied such freedom (Arminianism an exception).

Note the tertium quid - necessity, chance, and freedom

"You shall find in this little volume the questions concerning necessity, freedom, and chance, which in all ages have perplexed the minds of curious men, largely and clearly discussed, and the arguments on all sides, drawn from the authority of Scripture, from the doctrine of the Schools, from natural reason, and from the consequences pertaining to common life, truly alleged and severally weighed between two persons who both maintain that men are free to do as they will and to forbear as they will. The things they dissent in are that the one holds that it is not in a man's power now to choose the will he shall have anon; that chance produces nothing; that all events and actions have their necessary causes; that the will of God makes the necessity of all things. The other, on the contrary, maintains that not only the man is free to choose what he will do, but the will also to choose what it shall will; that when a man wills a good action, God's will concurs with his, else not; that the will may choose whether it will will or not; that many things come to pass without necessity, by chance; that though God foreknow a thing shall be, yet it is not necessary that that thing shall be, inasmuch as God sees not the future as in its causes but as present. In sum, they adhere both of them to the Scripture, but one of them is a learned School-divine, the other a man that does not much admire that kind of learning.

T.H.

The occasion of the controversy [namely the debates between Hobbes and Bishop Bramhall]

Whether whatsoever comes to pass proceed from necessity, or some things from chance, has been a question disputed amongst the old philosophers long time before the incarnation of our Saviour, without drawing into argument on either side the almighty power of the Deity.

But the third way of bringing things to pass, distinct from necessity and chance, namely, free-will, is a thing that never was mentioned amongst them, nor by the Christians in the beginning of Christianity. For Saint Paul, that disputes that question largely and purposely, never uses the term of `free-will'; nor did he hold any doctrine equivalent to that which is now called the doctrine of free-will, but derives all actions from the irresistible will of God, and nothing from the will of him that runs or wills. But for some ages past, the doctors of the Roman Church have exempted from this dominion of God's will the will of man, and brought in a doctrine that not only man but also his will is free, and determined to this or that action not by the will of God, nor necessary causes, but by the power of the will itself. And though by the reformed Churches instructed by Luther, Calvin, and others, this opinion was cast out; yet not many years since it began again to be reduced by Arminius and his followers, and became the readiest way to ecclesiastical promotion; and by discontenting those that held the contrary, was in some part the cause of the following troubles; which troubles were the occasion of my meeting with the Bishop of Derry at Paris, where we discoursed together of the argument now in hand; from which discourse we carried away each of us his own opinion, and for aught I remember, without any offensive words, as 'blasphemous', 'atheistical', or the like, passing between us; either for that the Bishop was not then in passion or suppressed his passion, being then in the presence of my Lord of Newcastle.

But afterwards the Bishop sent to his Lordship his opinion concerning the question in writing, and desired him to persuade me to send an answer thereunto likewise in writing. There were some reasons for which I thought it might be inconvenient to let my answer go abroad; yet the many obligations wherein I was obliged to him, prevailed with me to write this answer, which was afterwards, not only without my knowledge but also against my will, published by one that found means to get a copy of it surreptitiously. And thus you have the occasion of this controversy.

From Of Liberty and Necessity § 25- § 35, My opinion about liberty and necessity

§ 25 First, I conceive that when it comes into a man's mind to do or not to do some certain action, if he have no time to deliberate, the doing it or abstaining necessarily follows the present thought he has of the good or evil consequence thereof to himself As, for example, in sudden anger the action shall follow the thought of revenge, in sudden fear the thought of escape. Also when a man has time to deliberate but deliberates not, because never anything appeared that could make him doubt of the consequence, the action follows his opinion of the goodness or harm of it. These actions I call voluntary; my Lord [Bishop Bramhall], if I understand him aright, calls them spontaneous. I call them voluntary because those actions that follow immediately the last appetite are voluntary, and here where there is one only appetite that one is the last. Besides, I see it is reasonable to punish a rash action, which could not be justly done by man to man unless the same were voluntary. For no action of a man can be said to be without deliberation, though never so sudden, because it is supposed he had time to deliberate all the precedent time of his life whether he should do that kind of action or not. And hence it is that he that kills in a sudden passion of anger shall nevertheless be justly put to death, because all the time, wherein he was able to consider whether to kill were good or evil, shall be held for one continual deliberation; and consequently the killing shall be adjudged to proceed from election.

§ 26 Secondly, I conceive when a man deliberates whether he shall do a thing or not do it, that he does nothing else but consider whether it be better for himself to do it or not to do it. And to consider an action is to imagine the consequences of it, both good and evil. From whence is to be inferred, that deliberation is nothing but alternate imagination of the good and evil sequels of an action, or, which is the same thing, alternate hope and fear or alternate appetite to do or quit the action of which he deliberates.

§ 27 Thirdly, I conceive that in all deliberations, that is to say, in all alternate succession of contrary appetites, the last is that which we call the will, and is immediately next before the doing of the action, or next before the doing of it become impossible. All other appetites to do and to quit that come upon a man during his deliberation are usually called intentions and inclinations, but not wills; there being but one will, which also in this case may be called the last will, though the intention change often.

§ 28 Fourthly, that those actions which a man is said to do upon deliberation are said to be voluntary and done upon choice and election, so that voluntary action and action proceeding from election is the same thing; and that of a voluntary agent it is all one to say he is free, and to say he has not made an end of deliberating.

§ 29 Fifthly, I conceive liberty to be rightly defined in this manner: Liberty is the absence of all the impediments to action that are not contained in the nature and intrinsical quality of the agent. As, for example, the water is said to descend freely, or to have liberty to descend, by the channel of the river, because there is no impediment that way; but not across, because the banks are impediments. And though the water cannot ascend, yet men never say it wants the liberty to ascend, but the faculty or power, because the impediment is in the nature of the water and intrinsical. So also we say he that is tied wants the liberty to go, because the impediment is not in him but in his bands; whereas we say not so of him that is sick or lame, because the impediment is in himself.

§ 30 Sixthly, I conceive that nothing takes beginning from itself, but from the action of some other immediate agent without itself And that, therefore, when first a man has an appetite or will to something, to which immediately before he had no appetite nor will, the cause of his will is not the will itself, but something else not in his own disposing. So that whereas it is out of controversy that of voluntary actions the will is the necessary cause, and by this which is said the will is also caused by other things whereof it disposes not, it follows that voluntary actions have all of them necessary causes and therefore are necessitated.

§ 31 Seventhly, I hold that to be a sufficient cause to which nothing is wanting that is needful to the producing of the effect. The same also is a necessary cause. For if it be possible that a sufficient cause shall not bring forth the effect, then there wants somewhat which was needful to the producing of it, and so the cause was not sufficient. But if it be impossible that a sufficient cause should not produce the effect, then is a sufficient cause a necessary cause, for that is said to produce an effect necessarily that cannot but produce it. Hence it is manifest that whatsoever is produced is produced necessarily, for whatsoever is produced has a sufficient cause to produce it, or else it had not been; and therefore also voluntary actions are necessitated.

For Hobbes, one cannot do otherwise.

§ 32 Lastly, I hold that ordinary definition of a free agent, namely that a free agent is that which, when all things are present which are needful to produce the effect, can nevertheless not produce it, implies a contradiction and is nonsense; being as much as to say the cause may be sufficient, that is necessary, and yet the effect shall not follow.

My reasons

§ 33 For the first five points, where it is explicated, first, what spontaneity is, secondly, what deliberation is, thirdly, what will, propension, and appetite are, fourthly, what a free agent is, fifthly, what liberty is; there can no other proof be offered but every man's own experience, by reflection on himself and remembering what he uses to have in his mind; that is, what he himself means when he says an action is spontaneous, a man deliberates, such is his will, that action or that agent is free. Now he that so reflects on himself cannot but be satisfied that deliberation is the consideration of the good and evil sequels of an action to come; that by spontaneity is meant inconsiderate proceeding (or else nothing is meant by it); that will is the last act of our deliberation; that a free agent is he that can do if he will and forbear if he will; and that liberty is the absence of external impediments. But to those that out of custom speak not what they conceive but what they hear, and are not able or will not take the pains to consider what they think when they hear such words, no argument can be sufficient, because experience and matter of fact are not verified by other men's arguments but by every man's own sense and memory. For example, how can it be proved that to love a thing and to think it good are all one to a man that does not mark his own meaning by those words? Or how can it be proved that eternity is not nunc stans to a man that says those words by custom, and never considers how he can conceive the thing itself in his mind?

Also the sixth point, that a man cannot imagine anything to begin without a cause, can no other way be made known but by trying how he can imagine it. But if he try, he shall find as much reason, if there be no cause of the thing, to conceive it should begin at one time as at another, that is, he has equal reason to think it should begin at all times; which is impossible, and therefore he must think there was some special cause why it began then rather than sooner or later; or else that it began never, but was eternal.

§34 For the seventh point, which is that all events have necessary causes, it is there proved in that they have sufficient causes. Further let us in this place suppose any event never so casual, as, for example, the throwing ambs-ace upon a pair of dice, and see if it must not have been necessary before it was thrown. For seeing it was thrown, it had a beginning, and consequently a sufficient cause to produce it, consisting partly in the dice, partly in outward things, as the posture of the parts of the hand, the measure of force applied by the caster, the posture of the parts of the table, and the like. In sum, there was nothing wanting which was necessarily required to the producing of that particular cast, and consequently the cast was necessarily thrown. For if it had not been thrown, there had wanted somewhat requisite to the throwing of it, and so the cause had not been sufficient. In the like manner it may be proved that every other accident, how contingent soever it seem or how voluntary soever it be, is produced necessarily, which is that that my Lord Bishop disputes against. The same also may be proved in this manner. Let the case be put, for example, of the weather. It is necessary that tomorrow it shall rain or not rain. If therefore it be not necessary it shall rain, it is necessary it shall not rain; otherwise there is no necessity that the proposition, it shall rain or not rain, should be true. I know there be some that say, it may necessarily be true that one of the two shall come to pass, but not singly that it shall rain or that it shall not rain, which is as much as to say, one of them is necessary yet neither of them is necessary. And therefore to seem to avoid that absurdity, they make a distinction, that neither of them is true determinate [determinately], but indeterminate [indeterminately]; which distinction either signifies no more but this, one of them is true but we know not which, and so the necessity remains though we know it not; or if the meaning of the distinction be not that, it has no meaning, and they might as well have said, one of them is
true Tityrice but neither of them Tupatulice.

§ 35 The last thing, in which also consists the whole controversy, namely that there is no such thing as an agent which, when all things requisite to action are present, can nevertheless forbear to produce it; or, which is all one, that there is no such thing as freedom from necessity; is easily inferred from that which before has been alleged. For if it be an agent, it can work; and if it work, there is nothing wanting of what is requisite to produce the action, and consequently the cause of the action is sufficient; and if sufficient, then also necessary, as has been proved before.

§ 36 And thus you see how the inconveniences, which his Lordship objects must follow upon the holding of necessity, are avoided, and the necessity itself demonstratively proved. To which I could add, if I thought it good logic, the inconvenience of denying necessity, as that it destroys both the decrees and the prescience of God Almighty.

For Hobbes chance is atheistic

For whatsoever God has purposed to bring to pass by man as an instrument, or foresees shall come to pass, a man, if he have liberty (such as his Lordship affirms) from necessitation, might frustrate and make not to come to pass; and God should either not foreknow it and not decree it, or he should foreknow such things shall be as shall never be, and decree that which shall never come to pass.